In fall 2000, state officials and some of Maine’s business leaders were up in arms about a federal decision to list Atlantic salmon in eight Maine rivers as endangered species.

Critics predicted the designation could devastate an already weakened economy in Down East Maine by restricting blueberry growers’ water use, overregulating commercial forestry and forcing aquaculture operations out of business.

Eight years later, loggers are still working throughout the woods of Washington County. Blueberry harvests have been relatively strong in recent years. And while Maine’s aquaculture industry has struggled, observers say endangered wild salmon are just one of many factors.

The number of adult Atlantic salmon returning to the eight rivers, however, remains minuscule despite stronger federal protections and millions of dollars spent on salmon recovery projects since 2000.

All of those points undoubtedly will be raised in the coming months as federal regulators solicit feedback on a proposal to extend the endangered status to salmon in the Penobscot, Kennebec and Androscoggin rivers.

In 2000, state officials went as far as to file suit against the federal government to block listing of salmon populations in the Machias, East Machias, Narraguagus, Dennys, Pleasant, Ducktrap and Sheepscot rivers and Cove Brook.

So far, the proposal to expand those protections to salmon in Maine’s three largest rivers has been less controversial and political. It is likely to be more complicated, however.

Unlike the original eight, Maine’s three largest rivers all feature numerous dams, important heavy industry and considerable development. The Penobscot also features the only sizable run of spawning salmon in the U.S.

A federal “endangered” designation protects species from being killed, injured or harassed. Projects that require federal permits or receive federal money within species’ “critical habitat” must submit to an additional layer of regulatory review to ensure that the species will not be harmed.

Patrick Keliher, executive director of the Department of Marine Resources’ Bureau of Sea-Run Fisheries and Habitat, said he believes the science indicates that the fish are not at risk of extinction.

Instead, Keliher said the fish throughout the Gulf of Maine’s “distinct population segment” — meaning all salmon in the eight smaller and three large rivers — should be designated as “threatened” under the Endangered Species Act.

A threatened status still offers strong protections from harm but comes with less red tape and regulatory hoops that the state and its partners will have to leap through on recovery projects, he said.

“There needs to be some flexibility and creativity within the act and I don’t believe that is going to come unless [the status] is downgraded to threatened,” Keliher said.

Because federal agencies regard salmon in the eight smaller rivers and three large rivers as one population, any change in the designation would apply to all of the rivers.

Biologists with the National Marine Fisheries Service and the U.S. Fish and Wildlife Service have identified dams in the three rivers as one of the most significant threats to salmon recovery.

Scott Hall, manager of environmental services for PPL Maine, said it is unclear how an endangered or threatened designation would affect the company’s Penobscot dams.

A federal review would be triggered when a dam is up for relicensing or when a federal permit is required for other work. But dam owners likely would need to apply for an “incidental take permit” to protect themselves legally if salmon are killed or injured.

PPL has been actively working with the state, federal agencies and conservation groups on a landmark agreement to remove two dams and bypass a third in the Penobscot. In return, PPL was allowed to increase power generation at six other dams along the river.

Hall said all of the dams have some type of fish passage or will have new passages added as part of the Penobscot River restoration agreement. He said he expects all of restoration projects to continue regardless of the decision on the Penobscot salmon.

David Bell, executive director of the Wild Blueberry Commission of Maine, said growers began working to address water withdrawal concerns from Down East rivers several years before the 2000 designation.

That work has continued. What has been slower to happen, Bell said, is the federal implementation of much of the salmon recovery plans for the region. So Bell questioned how the underfunded and understaffed U.S. agencies would be able to expand their work to much larger watersheds.

Steven Koenig of Project S.H.A.R.E. said he is not aware of any major projects near the eight smaller rivers that were scuttled because of the designation.

Project S.H.A.R.E., which stands for Salmon Habitat and River Enhancement, works with private landowners, governments and conservation groups on habitat restoration Down East. Projects include replacing stream culverts and rebuilding logging roads responsible for siltation.

“My personal impression with regard to the listing is it’s a positive tool in that endangered species are automatically a high priority for federal funding,” he said.

The Atlantic Salmon Federation’s John Burrows agreed, pointing out that the designation brought millions of dollars into the region.

Even if salmon never fully recover Down East, fish such as brook trout or alewives and other wildlife have benefited from the habitat improvements, he said.

The Atlantic Salmon Federation supports protecting the three rivers’ salmon populations but has not taken a position on the endangered versus threatened question.

Keliher said the state wants to move cautiously after thorough research and analysis.

“We are trying to take the lessons we have learned Down East to figure out how to move forward on these larger rivers,” Keliher said. “We’ve learned a ton but what we’ve learned is we don’t have all of the answers.”